The correct option is A unequal and uneven curvature of eye lens
Answer is A.
Astigmatism is an optical defect in which vision is blurred due to the inability of the optics of the eye to focus a point object into a sharp focused image on the retina. This may be due to an irregular or toric curvature of the cornea or lens.
Hence, the disease of astigmatism in human eye is because of unequal and uneven curvature of eye lens.